Citizens Band (CB) Radio is a personal radio service at 27 MHz that anyone can use without a licence. Range is typically 1–5 miles mobile-to-mobile, up to 20 miles base-to-base. Under the right conditions, signals can bounce off the atmosphere and travel much farther (“skip”).

CB radio is used by truckers, off-roaders, farmers, and hobbyists. It’s fun because there are no contracts, no SIM cards, no internet – just you, your radio, and whoever is listening.

UK: Legal since 1981. 40 “27/81” FM channels and 40 CEPT channels, max 4 watts power.

US: 40 channels AM/FM/SSB, max 4 watts AM/FM, 12 watts PEP SSB. No licence required.

In both countries you don’t need to take a test or register – just buy a radio and start talking.

For vehicles:

1. Mount the radio securely within reach.
2. Connect power leads to a 12V supply with inline fuse.
3. Install the antenna (roof mag-mount, mirror mount, or bumper).
4. Route coax carefully away from heat and sharp edges.
5. Plug in the mic, power on, and adjust squelch.
6. Select channel 19 and key the mic: “Breaker one-nine, any copy?”

For home base setups:

1. Use a regulated 12V power supply.
2. Mount a base antenna high and clear of obstacles.
3. Run coax inside and connect to the radio.
4. Check SWR before long use.

SWR (Standing Wave Ratio) measures how well your antenna is matched to your radio. A poor match wastes power and can damage the transmitter.

• Good SWR = under 1.5:1
• Check with an SWR meter between the radio and antenna
• Tune by adjusting antenna length

10-4 = OK / I understand
Breaker 1-9 = I want to talk on channel 19
Handle = Your CB nickname
Smokey = Police
Rubber Duck = Lead truck in a convoy
Bear Trap = Police speed trap
What’s your 20? = What’s your location?

A dipole is one of the easiest antennas you can build. Two wires, each 2.59 m long, connected to coax – one wire to centre, one to shield. Hang as a straight line or inverted V.

Steps:

1. Cut 2 × 2.59 m wires.
2. Solder one to coax centre, one to shield.
3. Hang horizontally or in V-shape, at least 3 m above ground.
4. Tune with an SWR meter, trimming both wires equally.

This antenna uses a vertical radiator and four radials to form a ground plane.

Steps:

1. Use a 2.59 m vertical rod.
2. Attach 4 radials, each 2.59 m, angled at 45°.
3. Connect coax centre to vertical, shield to radials.
4. Mount high on a mast.

Repurpose a 2.6 m telescopic car aerial as a mobile CB antenna.

Steps:

1. Fit aerial to a mag-mount base with coax.
2. Extend whip fully.
3. Place mag-mount on vehicle roof.
4. Route coax to radio.
5. Tune by trimming whip length.

A stealthy antenna built from coax itself.

Steps:

1. Strip back 2.6 m of coax jacket.
2. Fold braid back as sleeve, leaving centre conductor as radiator.
3. Slide into PVC pipe for support.
4. Seal ends with tape.
5. Tune with SWR meter.